The Relationship Between Severity of Epilepsy and Sleep Disorder in Epileptic Children.

Objective
Sleep disturbances are one of the most common behavioral problems in childhood. Sleep problems have an even greater prevalence in children with epilepsy and are one of the most common comorbid conditions in childhood epilepsy.


Materials & Methods
This descriptive-correlation study with the general goal of determining the effects of epilepsy on sleep habits of epileptic children was conducted in Hamadan, western Iran, in 2014. Sampling was done using convenience sampling techniques. Data were collected using the Early Childhood Epilepsy Severity Scale (E-Chess) and Children's Sleep Habits Questionnaire (CSHQ) and analyzed using SPSS and descriptive and inferential statistics.


Results
The mean score of sleep habits was 55/08±6/71. Bedtime resistance (12/14±2/93), parasomnias (11/02±1/84) and sleep anxiety (8/29±2/46) were the most frequent sleep disorders in the studied sample. Based on Pearson's r, there were significant positive bidirectional relationships between bedtime resistance (rs =0.129, P<0.019), parasomnias (rs =0.298, P<0.005), sleep-disordered breathing (rs =0.295, P<0.005), CSHQ total score (rs =0.144, P<0.022) on the one hand, and children's epilepsy severity on the other.


Conclusion
Sleep problems should not be overlooked, and a comprehensive review of the sleep habits of this group of patients should be conducted.


Introduction
Seizures are short-term intermittent changes in movement or behavioral activities caused by abnormal electrical activities of the brain. Less than 1/3 of seizures in children are epileptic (1). Almost 1% of children suffer from epilepsy (2,3). Epilepsy is prevalent in developing countries including Iran where it is highly prevalent (1.8%) (4).
It is one of the commonest chronic neurological disorders and can negatively affect patients' lives (5). Epileptic children, compared with healthy ones, usually experience many behavioral and mental problems (5). This group of children, compared with their healthy peers, have more behavioral, emotional, and communicative issues which bring about dysfunctions in their performance and social abilities in society and school community (6). However, one of the prevalent yet commonly neglected behavioral problems of epileptic children is sleep disorders (5). Sufficient sleep and rest is a primary and basic need for survival and health in all age groups. Sleep quality, and not merely sleep quantity, is essential for desirable performance (7) and recovery from illness (8). People have their own habits and behavioral pattern of sleep, but it is a fact that following a regular schedule and having a good sleep habit facilitate the process of sleep and bring about a sense of rest upon waking. Bad sleep habits decrease the quality of sleep and cause physical and psychological-behavioral disorders (6) such as fatigue, lethargy, depression, negative attitudes, and disturbances in everyday schedule (9).
There is a complex, bidirectional relationship between sleep and epilepsy so that each variable can influence the other (5,10). Sleep-wake cycle relates to important changes in electrical activity of brain and also hormonal activities. Therefore, seizures and sleep-wake cycles are completely interrelated. Some people experience seizure while asleep or sleep-deprived, or upon waking up. In others, seizures happen during day or night (11).
Sleep phases alter the morphology of epileptiform discharges in a number of childhood epilepsy syndromes (12). Sleep has two main phases: 1.
Non-rapid eye movement (NREM), and 2. Rapid eye movements (REM). These two phases are caused by activities in various parts of the brain.  (2). Although epileptic and healthy children had similar sleep patterns and mean scores of CSHQ were high for both groups, these scores were higher for epileptics (except for subscores of sleep duration and daytime sleepiness) and they were, therefore, suffering from more severe sleep disorders (5). Number, type, and time of seizures may disrupt sleep-wake cycle, and anti-epileptic drugs (AEDs) affect the normal structure of sleep and reduce sleep sufficiency (7). The severity of epilepsy (including number and type of seizures, number of AEDs and their side-effects) was the only predictor of sleep disorders in epileptic children (12). Children with generalized seizures had more incidences of sleep disorder compared with those with focal seizures (16). Children and adolescents with drugresistant epilepsy, polytherapy, night seizures, and delayed growth show bad sleep habits, behaviors, and quality which may, in turn, negatively affect seizure control (16,17). However, no statistically significant difference was found between types of seizures and sleep disorders (5).  Sampling was done using convenience sampling techniques.

Inclusion and exclusion criteria
Inclusion criteria were as follows: 1) children's age must be in the range of 1 to 12 yr; 2) they should not be hospitalized during the course of study; 3) epilepsy must be diagnosed by a consulting physician; 4) they should not have used sedatives except for AEDs in the past 3 months; 5) they should not be afflicted by chronic respiratory diseases or sleep-related respiratory disorders; (6) they should not have other neurological disorders; and (7) parents or caretakers must be literate (2,5). (2 scores) for 2-4, and "rarely" (1 score) for 0-1. There are 2 items (Item 5 and 8) that are common to the bedtime resistance and sleep anxiety subscales.
A total score can be obtained by summing up the scores of the 33 items and the score range was 33-99. Subscale's scores can be obtained by summing up their respective items. The higher the total score (≥41), the child has more sleep problems (18). of anticonvulsant medications used were scored 0-3, and the total score was calculated by adding these two. The higher the total score, the more severe epilepsy (19).

Ethics approval
Letters of introduction were obtained from the Vice-

Demographic data
Overall, 49 (50%) boys and 49 (50%) girls with mean age and SD of 5 In "bedtime resistance" section, items "The child needs to be near his/her parents in order to fall sleep" (62.2%) and "The child is afraid of sleeping alone." (51%) were the most frequent ones (Usually). In "parasomnias" section, 93.9% of children rarely sleepwalked, while 78.6% usually were restless and moved a lot during sleep.
Under "daytime sleepiness", 74.5% of them rarely woke up in the morning by themselves, and 50.5% were usually drowsy or napped in the car.

Associations between sleep parameters and epilepsy
Another goal of this study was determining epilepsy severity and its relation with sleep habits.
Mean and SD of epilepsy severity in children As for the fourth goal of the study, that was, determining the relationship between sleep habits and type of AEDs; independent-samples t-tests were run. Results of comparing children who took sodium valproate with those who did not, on subscores of "night wakings" (P<0.011) and total score of CSHQ (P<0.120) were significant; these scores were higher for children who took this medication. Moreover, a significant difference was observed between children who took phenytoin and those who did not, on subscores of "nigh wakings" (P<0.13); these scores were higher for children who took this medication.  Here, a significant positive bidirectional relationship was observed between sections of "bedtime resistance", "parasomnias", "sleep- with generalized tonic-clonic seizures or idiopathic syndromes" (13). About, 75% of epileptic children took one, and 25% took more than one AEDs; the former had better sleep habits compared with the latter (16). Children and adolescents with drugresistant epilepsy, polytherapy, night seizures, and delayed growth show bad sleep habits, behaviors, and quality which may, in turn, negatively affect seizure control (16,23). Nevertheless, although 89% of children took AEDs (62% one, and 27% more than one); there was no significant difference between the number of medications and sleep problems (5).
There was a significant difference between children who took sodium valproate and those who did not, on subscale of "night waking's" and total score of CSHQ; moreover, there was a significant difference between children who took phenytoin and those who did not, on subscale of "night waking's". Sideeffects of AEDs are among the main obstacles of finding the right dose for controlling seizures. They include fatigue, drowsiness, imbalance, memory problems, and attention disorders. In addition, AEDs affect sleep duration, sleep latency, and sleep architecture (24)(25)(26). Sodium valproate is an AED.
This medication may increase NREM, decrease REM and excessive sleepiness (26). Termination of sodium valproate after long-term treatment can lead to a significant reduction in sleep duration in children older than 6 yr of age (27). Similar to this study, 55% of children were prescribed sodium valproate. Among AEDs, significant differences were observed between the use of sodium All authors agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.